Remember that you are not alone in trying to control your body language. Facial expressions, gestures or positions of a skilled orator will therefore show nothing. Feet can show you the thuth. Nervousness and fear are reflected in the movements of feet.
9. Authority
To gain authority, do not raise your voice. Before an important interview or phone call, find a while to relax and repeat the sound "uhm". Be sure that your voice is not too high and it goes down at the end of sentences.
10. Memory improvement
There is a research showing that you can remember more when listening to others with your hands or feet uncrossed.
Article source American Management Association - AMA official website